Installing Warcraft

Ok, I'm trying to install Warcraft 3 onto my 20" Intel iMac and I've been having some problems. The installation goes cleanly, but once I try to play, it opens, then after about 5 seconds, closes and a message pops up that says that "Warcraft III has unexpectedly quit and needs to shut down." Or something like that. Please, I need some help to fix this.

Ok, I'm trying to install Warcraft 3 onto my 20" Intel iMac and I've been having some problems. The installation goes cleanly, but once I try to play, it opens, then after about 5 seconds, closes and a message pops up that says that "Warcraft III has unexpectedly quit and needs to shut down." Or something like that. Please, I need some help to fix this.